From users-return-4095-daniel=haxx.se@subversion.apache.org Tue Aug 3 20:44:34 2010 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on giant.haxx.se X-Spam-Level: X-Spam-Status: No, score=-1.5 required=3.0 tests=BAYES_00,T_RP_MATCHES_RCVD autolearn=ham version=3.3.1 Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by giant.haxx.se (8.14.3/8.14.3/Debian-9.1) with SMTP id o73IiXVS032425 for ; Tue, 3 Aug 2010 20:44:33 +0200 Received: (qmail 59987 invoked by uid 500); 3 Aug 2010 18:44:24 -0000 Mailing-List: contact users-help@subversion.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list users@subversion.apache.org Received: (qmail 59980 invoked by uid 99); 3 Aug 2010 18:44:23 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 03 Aug 2010 18:44:23 +0000 X-ASF-Spam-Status: No, hits=0.7 required=10.0 tests=SPF_NEUTRAL Received-SPF: neutral (nike.apache.org: local policy) Received: from [213.41.242.187] (HELO prunille.vinc17.org) (213.41.242.187) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 03 Aug 2010 18:44:17 +0000 Received: by prunille.vinc17.org (Postfix, from userid 501) id 3514852CDB05; Tue, 3 Aug 2010 20:43:56 +0200 (CEST) Date: Tue, 3 Aug 2010 20:43:56 +0200 From: Vincent Lefevre To: users@subversion.apache.org Cc: Florian Weimer , Les Mikesell Subject: Re: Support for filesystem snapshots (?) Message-ID: <20100803184356.GK7288@prunille.vinc17.org> Mail-Followup-To: users@subversion.apache.org, Florian Weimer , Les Mikesell References: <6EC02A00CC9F684DAF4AF4084CA84D5F01C40CBC@DRMBX3.winmail.deshaw.com> <20100802175621.GL3967@ted.stsp.name> <6EC02A00CC9F684DAF4AF4084CA84D5F01C40CD7@DRMBX3.winmail.deshaw.com> <20100802202736.GO3967@ted.stsp.name> <6EC02A00CC9F684DAF4AF4084CA84D5F01C40CE1@DRMBX3.winmail.deshaw.com> <4C5730D3.8060507@gmail.com> <82eieg56kn.fsf@mid.bfk.de> <20100803105628.GA29679@jack.stsp.name> <20100803123641.GI7288@prunille.vinc17.org> <20100803131219.GB29679@jack.stsp.name> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20100803131219.GB29679@jack.stsp.name> X-Mailer-Info: http://www.vinc17.org/mutt/ User-Agent: Mutt/1.5.20-6088-vl-r38367 (2010-07-31) X-Virus-Checked: Checked by ClamAV on apache.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.3.5 (giant.haxx.se [80.67.6.50]); Tue, 03 Aug 2010 20:44:34 +0200 (CEST) X-Friend: Nope On 2010-08-03 15:12:19 +0200, Stefan Sperling wrote: > On Tue, Aug 03, 2010 at 02:36:41PM +0200, Vincent Lefevre wrote: > > On 2010-08-03 12:56:28 +0200, Stefan Sperling wrote: > > > Subversion carefully flushes file buffers after writing revision files. > > > > What do you mean by "flushes file buffers"? A call to fflush()? > > Or a call to sync() or fsync() too? > > > > Assuming the filesystem is on a remote machine (say, NFS), the > > necessary needs to be done on the client side: the NFS server > > cannot take into account the kernel-level buffers of the client. > > Subversion calls apr_file_flush(). What that does on which platform > depends on APR (and could theoretically change over time). > > I'm not sure what else you suggest we should do to avoid the (from > my point of view non-existent) bug you were talking about. Well, not flushing the buffers at some low level is not necessarily a bug. But in such a case the user has to accept the consequences, such as a filesystem snapshot not providing a consistent state of a Subversion repository. -- Vincent Lef�vre - Web: 100% accessible validated (X)HTML - Blog: Work: CR INRIA - computer arithmetic / Ar�naire project (LIP, ENS-Lyon)